Each replacement Locking Knob in this 5-pack from Manfrotto is compatible with a Manfrotto MVH500A 60mm Half Ball Fluid Video Head or MVH500AH Fluid Video Head with Flat Base. They are also compatible with the video heads included with a MVMXPRO500US XPRO Aluminum Video Monopod or MVM500A Video Monopod.
When installed on a compatible video head, any one of these locking knobs can be tightened or loosened to attach or remove the video head's quick release plate.
UPC: 719821366058